本 硏究는 31日齡 broiler 병아리에 297㎚의 紫外線을 照射하여 經過時間에 따라 다리의 皮膚를 採取하고 previtamin D₃(PreD₃), lumisterol₃(L₃), tachysterol₃(T₃), vitamin D₃(VD₃) 및 provitamin D₃(ProD₃) 含量을 測定코저 實施되었다. Broiler Hubbard系統 1日齡 병아리 82首(2照射時間×9 經過時間×4反覆+10對照區)를 無窓弱燈 肉鷄舍에 넣고 VD-缺乏飼料로 31日間 飼育한 後 照射線量 0.204mJ/㎠(30分 照射) 또는 0.409mJ/㎠(60分 照射)로 UVB 燈를 照射하였으며 0, 6, 12, 18, 30, 42, 66, 90 또는 138時間後에 다리의 皮膚를 採取하였다. 9% ethyl acetate/n-hexane으로 處理하여 脂質을 抽出하였으며 Sep-Pak silica cartridge로 精製한 後, 順相 HPLC로 PreD₃, L₃, T₃, VD₃ 및 ProD₃의 含量을 分析하였다. UVB를 照射하지 않은 對照區 병아리의 다리 皮膚中에는 PreD₃, L₃, T₃, VD₃가 檢出되지 않았으며 ProD₃ 含量은 966±89ng/㎠이었다. 0.204 또는 0.409mJ/㎠(30分 또는 60分) 照射時 다리 皮膚中 PreD₃의 mole %(절대함량. ng/㎠)는 照射直後 各各 4.67%(44ng/㎠) 또는 3.97%(37ng/㎠)이었으며 時間이 經過됨에 따라 점차 減少되었다. 병아리의 다리 皮膚 面積은 25.81±0.50㎠이었으며 다리 皮膚全體에서 合成된 PreD₃는 각각 0시간대에 961ng/chick, 738ng/chick이었다.
다리 皮膚中의 L₃은 0時間 經過時 各各 1.24%(12ng/㎠) 또는 0.92%(9ng/㎠)이었으며 時間이 지남에 따라 점차 減少되었다. T₃ 含量은 各各 0.58%(5ng/㎠) 또는 0.57%(6ng/㎠)이었으며 역시 時間의 經過와 더불어 減少되었다. VD₃含量은 0時間帶에 各各 2.13(21ng/㎠) 또는 0.97%(16ng/㎠), 12時間帶에 4.30%(33ng/㎠) 또는 6.40%(76ng/㎠)을 나타내었고 0.204mJ/㎠ 照射時에는 18時間帶에, 0.409mJ/㎠ 處理時에는 30時間後에 最高値를 보였다. PreD₃가 VD₃로 熱轉換되는데 各各 18 또는 30時間이 所要된다는 것을 示唆한다. 다리 皮膚中의 ProD₃ 含量은 0時間帶에 各各 948 또는 815ng/㎠이었으며 對照區의 ProD₃ 含量 966ng/㎠에 比하면 18 또는 151 ng/㎠의 ProD₃가 PreD₃, L₃, T₃ 및 VD₃로 異性化된 것이다. mole %로 보았을 때 各各 8.63%, 6.43%가 光合成物로 轉變된 것이다. 結論的으로 紫外線을 2倍 照射하였을 때 VD₃ 等 광생성물이 2倍는 아니지만 더 많이 生成된다는 것이 증명되었다.
This study was carried out to determine the concentrations of previtamin D₃(PreD₃), lumisterol₃(L₃), tachysterol₃(T₃), vitamin D₃(VD₃) and provitamin D₃(ProD₃) in leg skins of broiler chicks exposed to UVB lights(maximum intensity at 297 ㎚) with dose of 0.204 or 0.409 mJ / ㎠ (30 or 60 min irradiation). The broiler Hubbard line day old chicks(2 dose×9 elapsed time×4 replica+10 control=82) were fed VD-deficient diet for 31 days in a windowless subdued light room. The skin was collected at 0, 6, 12, 18, 30, 42, 66, 90 or 138 hr after UVB irradiation. The skin lipid was extracted by 9% ethyl acetate/n-hexane, and the fraction of VD₃ and its analogues was purified by Sep-Pak silica cartridge. The straight phase HPLC was utilized to analyze ProD₃ and its products. The mole %(absolute level expressed in ng/㎠) of PreD₃ in leg skin(epidermis+dermis) was 4.67%(44 ng/㎠) or 3.97%(37 ng/㎠) right after UVB irradiation by 0.204 or 0.409 mJ/㎠(30 or 60 min) at 15㎝ distance, respectively. L₃ content in leg skin at 0 hr after exposure was 7.24%(12 ng/㎠) or 0.92%(9 ng/㎠), respectively. The increase in irradiation dose did not affect proportionally the L₃ synthesis. T₃ concentration in leg skin was 0.58%(5 ng/㎠) or 0.57%(6 ng/㎠), respectively 0 hr after irradiation. The VD₃ in leg skin of birds exposed to UVB light with dose of 0.204 or 0.409 mJ/㎠ was 2.13%(21 ng/㎠) or 0.97% (16ng/㎠), respectively at 0 hr after exposure, 2.72%(26ng/㎠) or 3.84%(37ng/㎠), respectively at 6 hr, and 4.30%((33ng/㎠) or 6.40%(76ng/㎠), respectively at 12 hr. The peak concentration of VD₃ was presented at 18 or 30 hr when 0.204 or 0.409mJ/㎠) was treated, respectively. It was shown that 18~30 hr were necessary for the thermal conversion of PreD₃ into VD₃ in the leg skin of broiler chicks. The ProD₃ contents in leg skins of negative control, 0.204 mJ/㎠ and 0.409mJ/㎠ treated birds were 966, 948 and 815ng/㎠, respectively at right before and after UVB exposure. It was estimated that 18 or 151ng/㎠ of ProD₃ was isomerized to PreD₃, L₃, T₃ and VD₃ when exposed to 0.204 or 0.409mJ/㎠, respectively. Consequently it was shown that when double dose of UVB light was applied to irradiate the chick body, more but not double synthesis of VD₃ and its analogues was occured in leg skin of brolier chicks.